Plasma androgens and oestradiol during oral glucose tolerance test in patients with polycystic ovaries

Hyperinsulinaemia is common patients with polycystic ovaries (PCO), and a relationship between hyperinsulinaemia and hyperandrogenaemia has been suggested. We studied the effect of increased circulating insulin in response to an oral glucose tolerance test (OGTT) on plasma levels of androgens and oestradiol in PCO patients and in healthy control subjects. A 75 g, 3 h oral glucose tolerance test (OGTT) was performed in eight non-obese and seven obese PCO patients, and in 10 non-obese control subjects. An additional group of five women were fasting during the study period. The increase in insulin concentration was higher in obese and non-obese PCO patients than in non-obese control subjects, and the peak values were observed at 30 or 60 min. In the fasting control subjects, the mean concentration of androstenedione decreased slightly due to a diurnal variation. During the OGTT, mean concentrations of androstenedione decreased in all groups at 30 min, after which a slight increase was observed in PCO patients and a plateau in control subjects. Similarly, mean testosterone increased after an initial decrease in obese PCO patients whereas no change was found in non-obese PCO patients. No statistically significant differences were found in the responses of androstenedione or testosterone levels to OGTT in obese or non-obese PCO patients compared to normals. No significant responses of plasma oestradiol levels to OGTT were found. These findings failed to demonstrate any significantly abnormal acute androgen responses to OGTT-stimulated hyperinsulinaemia in PCO patients, but did not exclude possible long-term effects of hyperinsulinaemia.